In order to prevent a vessel from capsizing, there has been proposed a technique for reporting the risk of capsizing (for example, refer to Patent Document 1). With the invention disclosed in Patent Document 1, the risk of capsizing is determined by displaying limit value information about the possibility of capsizing that has been obtained on the basis of the hull motion data during navigation and the restoring performance information in the design phase. About the restoring performance information in the design phase, there is no specific description, however, in consideration of the existing naval architecture, it can be supposed to be hull information about the value of ship width, the center-of-gravity location, the buoyancy center location and the metacenter location which are in accordance with the inclination of the hull, and the like.